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RangerMauve / hyper-sdk

Make your own hyper apps!
https://www.youtube.com/watch?v=HyHk4aImd_I&list=PL7sG5SCUNyeYx8wnfMOUpsh7rM_g0w_cu&index=20
MIT License
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where does feed / signature validation take place when calling feed.append()? #83

Closed alexpmorris closed 3 years ago

alexpmorris commented 3 years ago

I recently did a test changing feed.secretKey after a few calls to feed.append(), then called feed.append() again. I expected the call to fail. However, it went through without a problem. If I manually called feed.verify() after that, only then did I receive a "Signature verification failed" error:

> await feed.verify(feed.length-1, feed._storage.signatures.toBuffer().slice(-64))
Uncaught Error: Signature verification failed

There was no replication or persistence with this test feed, so maybe that's part of the problem, as I don't expect it would be that easy to potentially corrupt a propagated feed.

But it also seems that by default, performing this sort of action using a key that doesn't match prior transactions should throw an error.

Appreciate any additional insight on this issue.

alexpmorris commented 3 years ago

I believe I found the answer, so closing this ticket. It seems anyone can append(), but if the invalid feed is propagated to another node, it would reject the tampered feed in _verifyAndWrite() -> _verifyRootsAndWrite(), thus throwing the exception Remote signature could not be verified.

RangerMauve commented 3 years ago

Glad you found an answer! For future reference, it might be good to post issues related to hypercore's internals to the hypercore repo